How can I reuse or recycle CNC milling blocks?

We’ve had a rather specific question from Douglas but we sometimes get incredibly informative responses to these type of questions so I thought it was worth posting in case anyone knows anything:

I was wondering if you knew of a way that I could reuse blocks that have been milled using a CNC machine (as known as rapid prototyping) The block are made out of zirconia and are use for the 3M Lava milling center. I hope you can help although i understand if not as this is and incredibly odd request since it is so specific.

So … anyone? I’ve not been able to find anything particularly useful on Google and I’ve sent a message to 3M about it but not heard anything back yet. Anyone else in a similar position?

Could do with knowing more about how big the blocks are, what shape etc and what properties this stuff has – do you have a photo of one? How many of them do you have?

Does it do anything interesting like rust or shatter or leech lime when left in water – or is it unusually stable like ceramic? Wikipedia makes me think it might be particularly scratch-resistant, and possibly a good insulator?